NEWS RELEASE, 5 JUNE 2024

Completion of process to transfer centinela's water supply Infrastructure

Antofagasta plc ("Antofagasta" or the "Company") is pleased to announce that, following the Company's earlier announcement dated 19 March 2024, the process to enter into a water transportation agreement by Minera Centinela ("Centinela"), involving its existing water supply and future water supply to the Centinela Second Concentrator Project, has now been completed.

Under the terms of the agreement, Centinela's existing water transportation assets and rights have been transferred to an international consortium formed of experienced partners, Transelec and Almar Water Solutions ("Almar"), with Centinela set to receive cash proceeds of $600 million during 2024. In addition, the planned expansion of the water transportation system will now be undertaken by the acquiring consortium, resulting in a reduction in the overall capital cost of the Centinela Second Concentrator Project by approximately $380 million, with this reduction to be realised over the course of the project's construction period. Following completion, the acquiring consortium will operate Centinela's existing water infrastructure.

The Company has assessed that the terms of the agreement are value accretive, as previously referenced in the Company's announcement in March. The acquiring consortium has a track record of building and operating infrastructure in Latin America, the Middle East and Asia, including existing projects in Chile.

Antofagasta's CEO, Iván Arriagada said: "Following today's news and the recently announced Centinela Second Concentrator Financing, we are in a good position to advance our growth ambitions in producing responsible copper for the global energy transition at a time when the global supply of copper has a limited ability to meet the expected medium-term rise in demand."

Antofagasta's CFO, Mauricio Ortiz said: "The agreement announced today is underpinned by our long-life resource base at Centinela and our capital allocation framework. By entering into this value accretive agreement, we have been able to reduce the capital intensity of the Centinela Second Concentrator Project, whilst protecting Centinela's competitiveness."

Centinela Second Concentrator Project

The Centinela Second Concentrator Project will add 170,000 tonnes of annual copper-equivalent production, comprising 144,000 tonnes of copper production and associated gold and molybdenum by-products.[1] Through this expansion, it is expected that Centinela will improve its cost competitiveness through an increased focus on concentrator capacity that incorporates modern technologies, increased by-products and greater economies of scale. First copper production from the project is expected in 2027.

Antofagasta is focused on responsible water use as part of its purpose of delivering mining for a better future. The Second Concentrator Project is an opportunity to provide additional copper from the Company's existing resource base using 100% renewable electricity and raw sea water.

About Transelec

Transelec (Transelec Group) is the leading provider of high voltage systems in Chile, with over 11,000 kilometres of transmission lines and more than 80 substations in Chile, powering 98% of Chile's population. Transelec is also present in Peru, through its fully owned subsidiary Conelsur, and in the water infrastructure industry, through its 40% stake in Aguas Horizonte.

About Almar Water Solutions

Almar Water Solutions, part of Jameel Environmental Services, is a leading company in the development of unconventional water infrastructure and production, distribution, and treatment services for both the municipal and industrial sectors. The company specializes in the development, design, management, financing, and operation of infrastructure, covering a wide range of solutions such as purification, desalination, treatment, and reuse. For more information, visit www.almarwater.com.

Register on our website to receive our email alerts at the following address: https://www.antofagasta.co.uk/investors/news/email-alerts/

_____________________________________________________________________________________________

Cautionary Statement

This announcement contains certain forward-looking statements. All statements other than historical facts are forward-looking statements. Examples of forward-looking statements include, without limitation, those regarding the Group's strategy, plans, objectives or future operating or financial performance, reserve and resource estimates, commodity demand and trends in commodity prices, growth opportunities, and any assumptions underlying or relating to any of the foregoing. Words such as "intend", "aim", "project", "anticipate", "estimate", "plan", "believe", "expect", "may", "should", "will", "continue" and similar expressions identify forward-looking statements.

Forward-looking statements involve known and unknown risks, uncertainties, assumptions and other factors that are beyond the Group's control. Given these risks, uncertainties and assumptions, actual results, performance or achievements could differ materially from any future results, performance or achievements expressed or implied by these forward-looking statements, which apply only as at the date of this report. These forward-looking statements are based on numerous assumptions regarding the Group's present and future business strategies and the environment in which the Group will operate in the future. Important factors that could cause actual results, performance or achievements to differ from those in the forward-looking statements include, but are not limited to: natural events, global economic and financial conditions (which may affect our business, results of operations or financial condition); various political, economic, legal, regulatory, social and other risks and uncertainties across jurisdictions in which the Group operates; changes to mining concessions or the imposition of new mining royalties, or changes to existing mining royalties in the jurisdictions in which the Group operates; the Group's ability to comply with the extensive body of regulations governing the mining industry, as well as the need to manage relationships with local communities; the ongoing effects of the global COVID-19 pandemic; demand, supply and prices for copper and other long-term commodity price assumptions (as they materially affect the timing and feasibility of future projects and developments); trends in the copper mining industry and conditions of the international copper markets; the effect of currency exchange rates on commodity prices and operating costs; the availability and costs associated with mining inputs and labour; operating or technical difficulties in connection with mining or development activities; risks, hazards and/or events and conditions inherent to the mining industry, which may affect our operations or facilities; employee relations; climate change as well as the effects of extreme weather conditions; the outcome of any litigation arbitration, regulatory or administrative proceedings to which the Group is and may be subject in the future; and actions and activities of governmental authorities, including changes to laws, regulations or taxation.

Except as required by applicable law, rule or regulation, the Group does not undertake any obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Past performance cannot be relied on as a guide to future performance.

No statement in this announcement is intended as a profit forecast or estimate for any period. No statement in this announcement should be interpreted to indicate a particular level of profit and, as a consequence, it should not be possible to derive a profit figure for any future period from this report.